/*
 * Copyright (c) 2010 Peter Hayes
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package org.envconfig.util;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Set;

/**
 * The main interface that the application uses to interact with the
 * configuration system.
 *
 * @author Pete Hayes
 */
public interface Configuration {

    /**
     * Return the set of keys available in this configuration
     *
     * @return The set of keys
     */
    public Set<String> keys();

    /**
     * Lookup the passed key and return the value as a String.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public String get(String key, String def);

    /**
     * Lookup the passed key and return the value as an Integer.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public Integer getInt(String key, Integer def);

    /**
     * Lookup the passed key and return the value as an Integer.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public BigInteger getBigInt(String key, BigInteger def);

    /**
     * Lookup the passed key and return the value as a Long.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public Long getLong(String key, Long def);

    /**
     * Lookup the passed key and return the value as a Float.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public Float getFloat(String key, Float def);

    /**
     * Lookup the passed key and return the value as a Double.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public Double getDouble(String key, Double def);

    /**
     * Lookup the passed key and return the value as a BigDecimal.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public BigDecimal getBigDecimal(String key, BigDecimal def);

    /**
     * Lookup the passed key and return the value as a Boolean.
     *
     * @param key The identifier
     * @param def The default value to return if the key was not found
     *
     * @return The configuration value
     */
    public Boolean getBoolean(String key, Boolean def);
}
